1. Field of the Invention
The present invention concerns a gyroscopic stabilizing device used to preserve an axial reference for a projectile controlling device, designed to modify the trajectory of this projectile. It more particularly concerns a device of this type mounted in a rocket.
2. Description of the Prior Art
A rocket is fired from an aircraft or helicopter at a great distance from the target. The aircraft takes an initial point as a reference and, consequently, its position with respect to the target is well defined. This firing mode is practiced with smooth bombs. It enables the aircraft to pull out in front of the target, where it is sheltered from hostile defenses.
Usually, rockets are fired in such conditions only with sub-projectiles which have their speed reduced by parachutes at the end of their trajectory. This method has two major drawbacks. First, the precision is relatively low. Second, all kinetic energy in the rocket is lost before impact whereas this is one of the most important characteristics of the weapon.
It is also observed that a standard rocket, launched without any braking parachute, reaches the ground at a very low angle of incidence with respect to the horizontal. In normal firing conditions, relating to angle and altitude, the sensitivity in regard to the point of impact would be very poor. Consequently, the firing would be very inaccurate.
The method used to improve firing precision consists in bending the end of the trajectory of the rocket so that it reaches the target with a high angle of incidence. Hence, a lateral force is applied to the rocket, said force being obtained by means of a control instrument. This device may be a lateral booster or an aerodynamic rudder.
To bend the trajectory of the rocket in the desired plane, which is generally the vertical plane, the control instrument should be positioned in this plane.
One method would consist in using a gyroscope providing information to a servo-control unit which, in response, will position the control instrument in the right plane. The rocket would then have to carry the entire servo-control mechanism as well as an energy source to power it. A device of this type is complicated and costly and is preferably reserved for more sophisticated missiles with longer trajectories and even more precise destinations.